索在静力和动力下均表现出较强的非线性特性，且受力索在满足一定频率比的边界激励下会发生振幅远超初始扰动的参数振动．针对悬索桥中存在的这一问题，文中考虑吊索前两阶模态，建立了以桥面振动为理想端部激励的吊索参数振动模型，并以矮寨特大悬索桥为工程算例，分析了成桥状态下吊索在端部激励下的一阶及二阶模态的参数振动，分别利用多尺度法和龙格一库塔数值法得到一致的吊索发生参数振动的条件及响应特性，并且分析了激励幅值、索长、初始扰动等因素对吊索共振响应幅值的影响．工程实例分析结果表明，大跨度悬索桥上的吊索在以桥面振动为参数激励的情况下有可能发生1：1主共振及1：2参数共振，激励幅值、索长、初始扰动等因素对吊索共振响应幅值及响应时间有一定的影响．

Cables of suspension bridges possess strong nonlinear characteristics under both static and dynamic forces,and,under the boundary excitation with certain frequency ratio,they may perform parametric vibration with the amplitude being much more than the initial value.In order to solve this problem,a parametric vibration model of suspender cable, which takes the bridge deck vibration as the boundary excitation and considers the first two or-der modals,was established.Then,by taking the super-large Aizhai suspension bridge as an engineering example,the first-order and the second-order parametric vibrations of the suspender cable under boundary excitation in the finished bridge state were analyzed,the same excited conditions and the response characteristics of parametric vibration of the suspender cable were determined by using the multi-scale method and the Runge-Kutta method,and the effects of excitation amplitude,cable length and initial disturbance on the resonant response amplitude were in-vestigated.The results indicate that the suspender cable of long-span suspension bridges under deck vibration may perfoIm a parametric vibration with the vibration ratio of 1:1 or 1:2,and that the excitation amplitude,the cable length and the initial disturbance affect the response amplitude and the response time to a certain degree.